Iodine deficiency is the most common preventable cause of mental deficiency. Remarkable success has been achieved by the use of iodised salt to correct this deficiency in many industrialised countries since 1920. The Government of India has adopted a strategy to iodise all edible salt in the country to overcome iodine deficiency. Universal salt iodisation is the principal public health measure for eliminating iodine deficiency disorders. Daily iodine intakes of up to 1000 micrograms, appear to be entirely safe. In India, the likelihood of exceeding this level is quite small. Iodised salt does not cause any side effects. Iodine in iodised salt does not carry risks for persons who are already iodine sufficient. iodisation of salt at the current level of fortification (15-30 ppm iodine) keeps intakes well within a safe daily range for all populations, irrespective of their iodine status.